The rise of electric vehicles and the fall of gas engines is a matter of when, not if

PLUG-IN HYBRID (PHEV) and ELECTRIC VEHICLES (BEV): The electrification of powertrains continues as automakers roll out everything from subcompact compliance cars to electrified supercars to improve efficiency and optimize power. Tesla Model 3 is just the prong on the charge cord of available plug-in vehicles. BMW, Mercedes-Benz, Ford, Volskwagen, Volvo, Hyundai have announced electrification plans for dozens of vehicles by 2020. Plug-in sales have grown 32 percent annually since 2013 (41 percent globally), and most autonomous vehicle plans are based on electric cars.

Electric vehicles no longer seem like a futuristic fever dream, but they remain a rarity on most American city streets, accounting for less than one percent of the nation's auto sales, according to the automotive website Edmunds.com.

Yet, when future auto historians look back, they may pinpoint 2017 as the year electric vehicles went from a promising progressive fad to an industry-wide inevitability.

The tipping point, experts say, follows three developments, each rippling outward with economic and cultural consequences.

Daimler AG plans to spend $1 billion to start production of Mercedes-Benz electric vehicles at its Alabama factory, setting the world's largest luxury-car maker up to battle with battery-car specialist Tesla on its home turf.

The German automaker will build its fifth battery plant globally and...

China's influence: In addition to setting aggressive production quotas for EVs, the world's largest auto market plans to scrap internal combustion engines entirely as soon as 2030.

The debut of Tesla's Model 3: The company's first mass-market vehicle has ushered in an era of excitement about EV's because of the car's slick design and starting price of around $35,000.

Major automakers ramp up electric vehicle plans: General Motors finished 2016 as the world's third-largest automaker, meaning its decision to create 20 new electric vehicles by 2023 is bound to have an impact on the global marketplace. Volvo, Volkswagen, Mercedes, Audi, BMW and Ford have also announced EV plans in recent months.

"You really do feel like this electrification thing is suddenly very real," Jessica Caldwell, executive director of industry analysis at Edmunds.com. "There's a momentum we haven't really seen before. It's coming from other countries around the world and from big automakers, and that's forcing everyone else to comply."

The all-electric future is still years away, experts say. But as EV momentum builds, we've listed five ways in which EV adoption is expected to play out:

The future of Big Oil

Not so long ago, minuscule sales of EVs made it hard for big oil to take the threat of electric cars seriously. Now, thanks to growing demand in Asia and Europe, the question facing experts is no longer whether EVs will take over, but when?

A Barclays' analysis concluded that oil demand could be slashed by 3.5 million barrels per day worldwide in 2025. If electric vehicle penetration reaches 33 percent, oil demand could shrink by a whopping 9 million barrels per day by 2040, Barclays concluded. Bloomberg's New Energy Finance puts the number at 8 million barrels by 2040, more than the "current combined production of Iran and Iraq," they note.

Urging caution about the impact of EVs on the oil industry, John Eichberger, executive director of the Fuels Institute, said he doesn't expect to see significant changes in demand for another 15 years or so. "We don't know how fast EV sales will pick up, but what we do know is that no matter how fast they pick up, the inventory in the market will turn over more slowly, and this will delay the impact on liquid gallon demand," he said.

"It's the vehicles on the road that will determine gasoline demand, not the vehicles being sold that day," he said.

Gas stations will change

Some experts believe electric cars have sounded the death knell of the American gas station, but others aren't so sure.

Until charging times drop dramatically and superchargers become widespread, wait times for EV charging at gas stations could turn those stations into "hospitality-type venues," according to Guido Jouret, the ABB's chief digital officer, who noted that many gas stations make more money selling soda and food than they do selling gas.

"The idea is that for hospitality-type venues—restaurants, gas stations, coffee shops—electric vehicle charging could be an attractive way for them to attract customers the way WiFi was a decade ago, when it caused a lot of people to hang out at Starbucks."

Depending on how electricity is produced in your region, plug-ins are from 30 percent to 80 percent lower in greenhouse gas emissions, according to Gina Coplon-Newfield, the director of the Sierra Club's Electric Vehicles Initiative.

If GM's 2016 U.S. sales—more than 3 million vehicles—were converted to EV's, the country would benefit in the following ways, according to an analysis provided by the Sierra Club:

6.5 million tons, or 13 billion pounds, of GHGs reduced annually.

35.6 million barrels of petroleum reduced annually, creating less of a dependency on foreign oil, further boosting demand on domestic electricity and keeping oil money spent in-state.

One of the primary reasons that auto owners visit a mechanic is for an oil change, which raises a question: What happens when vehicles no longer rely on oil? It's not that electric vehicles won't require maintenance (they still have brakes, tires and windshield wipers, after all), but their engines are far simpler, experts say.

"Basically these things don't break," Tony Seba, a clean energy expert and the founder of RethinkX, a think tank that forecasts changes in the transportation industry. "They have 20 moving parts, as opposed to 2,000 in the internal combustion engine, and even those 20 are electromagnetic, which means they don't touch and don't break down and, therefore, are far cheaper to maintain."

Seba pointed out that there are thousands of department store and dealer repair locationsas well as about 70,000 mom-and-pop repair shopsthat will be significantly affected by a decline in business.

Powering the grid

We tend to think of EVs as consumers of electricity, but some experts believe they'll be more like "mobile energy storage units," as Forbes recently noted. Widespread adoption, experts say, may allow vehicles to transfer energy back to the grid when costs and demand are high and charge the battery when demand has waned.